Relative Motion: Moe's Corridor Walk Time

[Gold3nlily]

Relative Motion: moving sidewalk!

Homework Statement

An airport terminal has a moving sidewalk to speed passengers through a long corridor. Larry does not use the moving sidewalk; he takes 140 s to walk through the corridor. Curly, who simply stands on the moving sidewalk, covers the same distance in 65 s. Moe boards the sidewalk and walks along it. How long does Moe take to move through the corridor? Assume that Larry and Moe walk at the same speed.

Homework Equations

VAC = VAB + VBC
d=vt

The Attempt at a Solution

This problem is from the relative motion section of my textbook, but it doesn't specify the reference point. I am assuming the reference point (RP) is the ground and that it is in front of the moving side walk.

RP --------------------------------------------> (moving sidewalk)

all three trips move the same amount of distance (d).
Vwalk = d/140 sec
Vride = d/65 sec
d=vt (but d is same so...)
Vw(140)=Vr(65) ---> so still have two variables...?!

I also tried:
Vwg= d/140 sec (g = ground)
Vrg = d/65 sec
Vwr ... doesn't work. Vrg would have to become Vgr.

I am totally lost on this problem. It is embarrassing. Can someone please walk me through it with hints? I would really appreciate it.

I would also be grateful for any general advice about how to solve problems that seem under represented by the textbook or advice about how to handle stress when I cannot figure out a problem on my own. Some of these physics problems really blow my academic confidence and I am only in physics 1! I need to learn how to think more like a physicist.

 

[AvroArrow]

Answer: Moe's trip through the corridor will take 97 seconds.To solve this problem, you need to use the equation VAC = VAB + VBC. This equation states that the velocity of the final object (C) is equal to the sum of the velocities of the two other objects (A and B). In this case, we can assume that A is Larry walking on the ground and B is the moving sidewalk. The velocity of C is then Moe's velocity, which we want to find.Using this equation, we can set up an equation to solve for Moe's velocity. Larry's velocity, VAG, is d/140, where d is the distance traveled. The velocity of the moving sidewalk, VBG, is d/65. Therefore, we can set up the equation as follows:VAC = VAG + VBGVAC = (d/140) + (d/65)Solving for VAC gives us VAC = d/97. Since the velocity of C is Moe's velocity, this means that Moe takes 97 seconds to move through the corridor.